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Merge git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/sysctl

Browse source 
Pull sysctl updates from Eric Biederman:

 - Rewrite of sysctl for speed and clarity.

   Insert/remove/Lookup in sysctl are all now O(NlogN) operations, and
   are no longer bottlenecks in the process of adding and removing
   network devices.

   sysctl is now focused on being a filesystem instead of system call
   and the code can all be found in fs/proc/proc_sysctl.c.  Hopefully
   this means the code is now approachable.

   Much thanks is owed to Lucian Grinjincu for keeping at this until
   something was found that was usable.

 - The recent proc_sys_poll oops found by the fuzzer during hibernation
   is fixed.

* git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/sysctl: (36 commits)
  sysctl: protect poll() in entries that may go away
  sysctl: Don't call sysctl_follow_link unless we are a link.
  sysctl: Comments to make the code clearer.
  sysctl: Correct error return from get_subdir
  sysctl: An easier to read version of find_subdir
  sysctl: fix memset parameters in setup_sysctl_set()
  sysctl: remove an unused variable
  sysctl: Add register_sysctl for normal sysctl users
  sysctl: Index sysctl directories with rbtrees.
  sysctl: Make the header lists per directory.
  sysctl: Move sysctl_check_dups into insert_header
  sysctl: Modify __register_sysctl_paths to take a set instead of a root and an nsproxy
  sysctl: Replace root_list with links between sysctl_table_sets.
  sysctl: Add sysctl_print_dir and use it in get_subdir
  sysctl: Stop requiring explicit management of sysctl directories
  sysctl: Add a root pointer to ctl_table_set
  sysctl: Rewrite proc_sys_readdir in terms of first_entry and next_entry
  sysctl: Rewrite proc_sys_lookup introducing find_entry and lookup_entry.
  sysctl: Normalize the root_table data structure.
  sysctl: Factor out insert_header and erase_header
  ...
This commit is contained in:
Linus Torvalds 2012-03-23 18:08:58 -07:00
commit f1d38e423a
8 changed files with 1280 additions and 797 deletions
repo.diff.show_diff_stats Download patch file Download diff file Expand all files Collapse all files

3
fs/proc/internal.h
View file

@ -10,12 +10,15 @@
*/ */
#include <linux/proc_fs.h> #include <linux/proc_fs.h>
struct ctl_table_header;
extern struct proc_dir_entry proc_root; extern struct proc_dir_entry proc_root;
#ifdef CONFIG_PROC_SYSCTL #ifdef CONFIG_PROC_SYSCTL
extern int proc_sys_init(void); extern int proc_sys_init(void);
extern void sysctl_head_put(struct ctl_table_header *head);
#else #else
static inline void proc_sys_init(void) { } static inline void proc_sys_init(void) { }
static inline void sysctl_head_put(struct ctl_table_header *head) { }
#endif #endif
#ifdef CONFIG_NET #ifdef CONFIG_NET
extern int proc_net_init(void); extern int proc_net_init(void);

1276
fs/proc/proc_sysctl.c
View file

File diff suppressed because it is too large Load diff

106
include/linux/sysctl.h
View file

@ -932,34 +932,14 @@ enum
#include <linux/list.h> #include <linux/list.h>
#include <linux/rcupdate.h> #include <linux/rcupdate.h>
#include <linux/wait.h> #include <linux/wait.h>
#include <linux/rbtree.h>
/* For the /proc/sys support */ /* For the /proc/sys support */
struct ctl_table; struct ctl_table;
struct nsproxy; struct nsproxy;
struct ctl_table_root; struct ctl_table_root;
struct ctl_table_set {
struct list_head list;
struct ctl_table_set *parent;
int (*is_seen)(struct ctl_table_set *);
};
extern void setup_sysctl_set(struct ctl_table_set *p,
struct ctl_table_set *parent,
int (*is_seen)(struct ctl_table_set *));
struct ctl_table_header; struct ctl_table_header;
struct ctl_dir;
extern void sysctl_head_get(struct ctl_table_header *);
extern void sysctl_head_put(struct ctl_table_header *);
extern int sysctl_is_seen(struct ctl_table_header *);
extern struct ctl_table_header *sysctl_head_grab(struct ctl_table_header *);
extern struct ctl_table_header *sysctl_head_next(struct ctl_table_header *prev);
extern struct ctl_table_header *__sysctl_head_next(struct nsproxy *namespaces,
struct ctl_table_header *prev);
extern void sysctl_head_finish(struct ctl_table_header *prev);
extern int sysctl_perm(struct ctl_table_root *root,
struct ctl_table *table, int op);
typedef struct ctl_table ctl_table; typedef struct ctl_table ctl_table;
@ -1023,8 +1003,6 @@ static inline void *proc_sys_poll_event(struct ctl_table_poll *poll)
return (void *)(unsigned long)atomic_read(&poll->event); return (void *)(unsigned long)atomic_read(&poll->event);
} }
void proc_sys_poll_notify(struct ctl_table_poll *poll);
#define __CTL_TABLE_POLL_INITIALIZER(name) { \ #define __CTL_TABLE_POLL_INITIALIZER(name) { \
.event = ATOMIC_INIT(0), \ .event = ATOMIC_INIT(0), \
.wait = __WAIT_QUEUE_HEAD_INITIALIZER(name.wait) } .wait = __WAIT_QUEUE_HEAD_INITIALIZER(name.wait) }
@ -1039,21 +1017,16 @@ struct ctl_table
void *data; void *data;
int maxlen; int maxlen;
umode_t mode; umode_t mode;
struct ctl_table *child; struct ctl_table *child; /* Deprecated */
struct ctl_table *parent; /* Automatically set */
proc_handler *proc_handler; /* Callback for text formatting */ proc_handler *proc_handler; /* Callback for text formatting */
struct ctl_table_poll *poll; struct ctl_table_poll *poll;
void *extra1; void *extra1;
void *extra2; void *extra2;
}; };
struct ctl_table_root { struct ctl_node {
struct list_head root_list; struct rb_node node;
struct ctl_table_set default_set; struct ctl_table_header *header;
struct ctl_table_set *(*lookup)(struct ctl_table_root *root,
struct nsproxy *namespaces);
int (*permissions)(struct ctl_table_root *root,
struct nsproxy *namespaces, struct ctl_table *table);
}; };
/* struct ctl_table_header is used to maintain dynamic lists of /* struct ctl_table_header is used to maintain dynamic lists of
@ -1063,9 +1036,9 @@ struct ctl_table_header
union { union {
struct { struct {
struct ctl_table *ctl_table; struct ctl_table *ctl_table;
struct list_head ctl_entry;
int used; int used;
int count; int count;
int nreg;
}; };
struct rcu_head rcu; struct rcu_head rcu;
}; };
@ -1073,9 +1046,27 @@ struct ctl_table_header
struct ctl_table *ctl_table_arg; struct ctl_table *ctl_table_arg;
struct ctl_table_root *root; struct ctl_table_root *root;
struct ctl_table_set *set; struct ctl_table_set *set;
struct ctl_table *attached_by; struct ctl_dir *parent;
struct ctl_table *attached_to; struct ctl_node *node;
struct ctl_table_header *parent; };
struct ctl_dir {
/* Header must be at the start of ctl_dir */
struct ctl_table_header header;
struct rb_root root;
};
struct ctl_table_set {
int (*is_seen)(struct ctl_table_set *);
struct ctl_dir dir;
};
struct ctl_table_root {
struct ctl_table_set default_set;
struct ctl_table_set *(*lookup)(struct ctl_table_root *root,
struct nsproxy *namespaces);
int (*permissions)(struct ctl_table_root *root,
struct nsproxy *namespaces, struct ctl_table *table);
}; };
/* struct ctl_path describes where in the hierarchy a table is added */ /* struct ctl_path describes where in the hierarchy a table is added */
@ -1083,16 +1074,53 @@ struct ctl_path {
const char *procname; const char *procname;
}; };
#ifdef CONFIG_SYSCTL
void proc_sys_poll_notify(struct ctl_table_poll *poll);
extern void setup_sysctl_set(struct ctl_table_set *p,
struct ctl_table_root *root,
int (*is_seen)(struct ctl_table_set *));
extern void retire_sysctl_set(struct ctl_table_set *set);
void register_sysctl_root(struct ctl_table_root *root); void register_sysctl_root(struct ctl_table_root *root);
struct ctl_table_header *__register_sysctl_table(
struct ctl_table_set *set,
const char *path, struct ctl_table *table);
struct ctl_table_header *__register_sysctl_paths( struct ctl_table_header *__register_sysctl_paths(
struct ctl_table_root *root, struct nsproxy *namespaces, struct ctl_table_set *set,
const struct ctl_path *path, struct ctl_table *table); const struct ctl_path *path, struct ctl_table *table);
struct ctl_table_header *register_sysctl(const char *path, struct ctl_table *table);
struct ctl_table_header *register_sysctl_table(struct ctl_table * table); struct ctl_table_header *register_sysctl_table(struct ctl_table * table);
struct ctl_table_header *register_sysctl_paths(const struct ctl_path *path, struct ctl_table_header *register_sysctl_paths(const struct ctl_path *path,
struct ctl_table *table); struct ctl_table *table);
void unregister_sysctl_table(struct ctl_table_header * table); void unregister_sysctl_table(struct ctl_table_header * table);
int sysctl_check_table(struct nsproxy *namespaces, struct ctl_table *table);
extern int sysctl_init(void);
#else /* CONFIG_SYSCTL */
static inline struct ctl_table_header *register_sysctl_table(struct ctl_table * table)
{
return NULL;
}
static inline struct ctl_table_header *register_sysctl_paths(
const struct ctl_path *path, struct ctl_table *table)
{
return NULL;
}
static inline void unregister_sysctl_table(struct ctl_table_header * table)
{
}
static inline void setup_sysctl_set(struct ctl_table_set *p,
struct ctl_table_root *root,
int (*is_seen)(struct ctl_table_set *))
{
}
#endif /* CONFIG_SYSCTL */
#endif /* __KERNEL__ */ #endif /* __KERNEL__ */

1
kernel/Makefile
View file

@ -27,7 +27,6 @@ obj-y += power/
obj-$(CONFIG_FREEZER) += freezer.o obj-$(CONFIG_FREEZER) += freezer.o
obj-$(CONFIG_PROFILING) += profile.o obj-$(CONFIG_PROFILING) += profile.o
obj-$(CONFIG_SYSCTL_SYSCALL_CHECK) += sysctl_check.o
obj-$(CONFIG_STACKTRACE) += stacktrace.o obj-$(CONFIG_STACKTRACE) += stacktrace.o
obj-y += time/ obj-y += time/
obj-$(CONFIG_DEBUG_MUTEXES) += mutex-debug.o obj-$(CONFIG_DEBUG_MUTEXES) += mutex-debug.o

501
kernel/sysctl.c
View file

@ -193,20 +193,6 @@ static int sysrq_sysctl_handler(ctl_table *table, int write,
#endif #endif
static struct ctl_table root_table[];
static struct ctl_table_root sysctl_table_root;
static struct ctl_table_header root_table_header = {
{{.count = 1,
.ctl_table = root_table,
.ctl_entry = LIST_HEAD_INIT(sysctl_table_root.default_set.list),}},
.root = &sysctl_table_root,
.set = &sysctl_table_root.default_set,
};
static struct ctl_table_root sysctl_table_root = {
.root_list = LIST_HEAD_INIT(sysctl_table_root.root_list),
.default_set.list = LIST_HEAD_INIT(root_table_header.ctl_entry),
};
static struct ctl_table kern_table[]; static struct ctl_table kern_table[];
static struct ctl_table vm_table[]; static struct ctl_table vm_table[];
static struct ctl_table fs_table[]; static struct ctl_table fs_table[];
@ -223,7 +209,7 @@ int sysctl_legacy_va_layout;
/* The default sysctl tables: */ /* The default sysctl tables: */
static struct ctl_table root_table[] = { static struct ctl_table sysctl_base_table[] = {
{ {
.procname = "kernel", .procname = "kernel",
.mode = 0555, .mode = 0555,
@ -1560,488 +1546,10 @@ static struct ctl_table dev_table[] = {
{ } { }
}; };
static DEFINE_SPINLOCK(sysctl_lock); int __init sysctl_init(void)
/* called under sysctl_lock */
static int use_table(struct ctl_table_header *p)
{ {
if (unlikely(p->unregistering)) register_sysctl_table(sysctl_base_table);
return 0; return 0;
p->used++;
return 1;
}
/* called under sysctl_lock */
static void unuse_table(struct ctl_table_header *p)
{
if (!--p->used)
if (unlikely(p->unregistering))
complete(p->unregistering);
}
/* called under sysctl_lock, will reacquire if has to wait */
static void start_unregistering(struct ctl_table_header *p)
{
/*
* if p->used is 0, nobody will ever touch that entry again;
* we'll eliminate all paths to it before dropping sysctl_lock
*/
if (unlikely(p->used)) {
struct completion wait;
init_completion(&wait);
p->unregistering = &wait;
spin_unlock(&sysctl_lock);
wait_for_completion(&wait);
spin_lock(&sysctl_lock);
} else {
/* anything non-NULL; we'll never dereference it */
p->unregistering = ERR_PTR(-EINVAL);
}
/*
* do not remove from the list until nobody holds it; walking the
* list in do_sysctl() relies on that.
*/
list_del_init(&p->ctl_entry);
}
void sysctl_head_get(struct ctl_table_header *head)
{
spin_lock(&sysctl_lock);
head->count++;
spin_unlock(&sysctl_lock);
}
void sysctl_head_put(struct ctl_table_header *head)
{
spin_lock(&sysctl_lock);
if (!--head->count)
kfree_rcu(head, rcu);
spin_unlock(&sysctl_lock);
}
struct ctl_table_header *sysctl_head_grab(struct ctl_table_header *head)
{
if (!head)
BUG();
spin_lock(&sysctl_lock);
if (!use_table(head))
head = ERR_PTR(-ENOENT);
spin_unlock(&sysctl_lock);
return head;
}
void sysctl_head_finish(struct ctl_table_header *head)
{
if (!head)
return;
spin_lock(&sysctl_lock);
unuse_table(head);
spin_unlock(&sysctl_lock);
}
static struct ctl_table_set *
lookup_header_set(struct ctl_table_root *root, struct nsproxy *namespaces)
{
struct ctl_table_set *set = &root->default_set;
if (root->lookup)
set = root->lookup(root, namespaces);
return set;
}
static struct list_head *
lookup_header_list(struct ctl_table_root *root, struct nsproxy *namespaces)
{
struct ctl_table_set *set = lookup_header_set(root, namespaces);
return &set->list;
}
struct ctl_table_header *__sysctl_head_next(struct nsproxy *namespaces,
struct ctl_table_header *prev)
{
struct ctl_table_root *root;
struct list_head *header_list;
struct ctl_table_header *head;
struct list_head *tmp;
spin_lock(&sysctl_lock);
if (prev) {
head = prev;
tmp = &prev->ctl_entry;
unuse_table(prev);
goto next;
}
tmp = &root_table_header.ctl_entry;
for (;;) {
head = list_entry(tmp, struct ctl_table_header, ctl_entry);
if (!use_table(head))
goto next;
spin_unlock(&sysctl_lock);
return head;
next:
root = head->root;
tmp = tmp->next;
header_list = lookup_header_list(root, namespaces);
if (tmp != header_list)
continue;
do {
root = list_entry(root->root_list.next,
struct ctl_table_root, root_list);
if (root == &sysctl_table_root)
goto out;
header_list = lookup_header_list(root, namespaces);
} while (list_empty(header_list));
tmp = header_list->next;
}
out:
spin_unlock(&sysctl_lock);
return NULL;
}
struct ctl_table_header *sysctl_head_next(struct ctl_table_header *prev)
{
return __sysctl_head_next(current->nsproxy, prev);
}
void register_sysctl_root(struct ctl_table_root *root)
{
spin_lock(&sysctl_lock);
list_add_tail(&root->root_list, &sysctl_table_root.root_list);
spin_unlock(&sysctl_lock);
}
/*
* sysctl_perm does NOT grant the superuser all rights automatically, because
* some sysctl variables are readonly even to root.
*/
static int test_perm(int mode, int op)
{
if (!current_euid())
mode >>= 6;
else if (in_egroup_p(0))
mode >>= 3;
if ((op & ~mode & (MAY_READ|MAY_WRITE|MAY_EXEC)) == 0)
return 0;
return -EACCES;
}
int sysctl_perm(struct ctl_table_root *root, struct ctl_table *table, int op)
{
int mode;
if (root->permissions)
mode = root->permissions(root, current->nsproxy, table);
else
mode = table->mode;
return test_perm(mode, op);
}
static void sysctl_set_parent(struct ctl_table *parent, struct ctl_table *table)
{
for (; table->procname; table++) {
table->parent = parent;
if (table->child)
sysctl_set_parent(table, table->child);
}
}
static __init int sysctl_init(void)
{
sysctl_set_parent(NULL, root_table);
#ifdef CONFIG_SYSCTL_SYSCALL_CHECK
sysctl_check_table(current->nsproxy, root_table);
#endif
return 0;
}
core_initcall(sysctl_init);
static struct ctl_table *is_branch_in(struct ctl_table *branch,
struct ctl_table *table)
{
struct ctl_table *p;
const char *s = branch->procname;
/* branch should have named subdirectory as its first element */
if (!s || !branch->child)
return NULL;
/* ... and nothing else */
if (branch[1].procname)
return NULL;
/* table should contain subdirectory with the same name */
for (p = table; p->procname; p++) {
if (!p->child)
continue;
if (p->procname && strcmp(p->procname, s) == 0)
return p;
}
return NULL;
}
/* see if attaching q to p would be an improvement */
static void try_attach(struct ctl_table_header *p, struct ctl_table_header *q)
{
struct ctl_table *to = p->ctl_table, *by = q->ctl_table;
struct ctl_table *next;
int is_better = 0;
int not_in_parent = !p->attached_by;
while ((next = is_branch_in(by, to)) != NULL) {
if (by == q->attached_by)
is_better = 1;
if (to == p->attached_by)
not_in_parent = 1;
by = by->child;
to = next->child;
}
if (is_better && not_in_parent) {
q->attached_by = by;
q->attached_to = to;
q->parent = p;
}
}
/**
* __register_sysctl_paths - register a sysctl hierarchy
* @root: List of sysctl headers to register on
* @namespaces: Data to compute which lists of sysctl entries are visible
* @path: The path to the directory the sysctl table is in.
* @table: the top-level table structure
*
* Register a sysctl table hierarchy. @table should be a filled in ctl_table
* array. A completely 0 filled entry terminates the table.
*
* The members of the &struct ctl_table structure are used as follows:
*
* procname - the name of the sysctl file under /proc/sys. Set to %NULL to not
* enter a sysctl file
*
* data - a pointer to data for use by proc_handler
*
* maxlen - the maximum size in bytes of the data
*
* mode - the file permissions for the /proc/sys file, and for sysctl(2)
*
* child - a pointer to the child sysctl table if this entry is a directory, or
* %NULL.
*
* proc_handler - the text handler routine (described below)
*
* de - for internal use by the sysctl routines
*
* extra1, extra2 - extra pointers usable by the proc handler routines
*
* Leaf nodes in the sysctl tree will be represented by a single file
* under /proc; non-leaf nodes will be represented by directories.
*
* sysctl(2) can automatically manage read and write requests through
* the sysctl table. The data and maxlen fields of the ctl_table
* struct enable minimal validation of the values being written to be
* performed, and the mode field allows minimal authentication.
*
* There must be a proc_handler routine for any terminal nodes
* mirrored under /proc/sys (non-terminals are handled by a built-in
* directory handler). Several default handlers are available to
* cover common cases -
*
* proc_dostring(), proc_dointvec(), proc_dointvec_jiffies(),
* proc_dointvec_userhz_jiffies(), proc_dointvec_minmax(),
* proc_doulongvec_ms_jiffies_minmax(), proc_doulongvec_minmax()
*
* It is the handler's job to read the input buffer from user memory
* and process it. The handler should return 0 on success.
*
* This routine returns %NULL on a failure to register, and a pointer
* to the table header on success.
*/
struct ctl_table_header *__register_sysctl_paths(
struct ctl_table_root *root,
struct nsproxy *namespaces,
const struct ctl_path *path, struct ctl_table *table)
{
struct ctl_table_header *header;
struct ctl_table *new, **prevp;
unsigned int n, npath;
struct ctl_table_set *set;
/* Count the path components */
for (npath = 0; path[npath].procname; ++npath)
;
/*
* For each path component, allocate a 2-element ctl_table array.
* The first array element will be filled with the sysctl entry
* for this, the second will be the sentinel (procname == 0).
*
* We allocate everything in one go so that we don't have to
* worry about freeing additional memory in unregister_sysctl_table.
*/
header = kzalloc(sizeof(struct ctl_table_header) +
(2 * npath * sizeof(struct ctl_table)), GFP_KERNEL);
if (!header)
return NULL;
new = (struct ctl_table *) (header + 1);
/* Now connect the dots */
prevp = &header->ctl_table;
for (n = 0; n < npath; ++n, ++path) {
/* Copy the procname */
new->procname = path->procname;
new->mode = 0555;
*prevp = new;
prevp = &new->child;
new += 2;
}
*prevp = table;
header->ctl_table_arg = table;
INIT_LIST_HEAD(&header->ctl_entry);
header->used = 0;
header->unregistering = NULL;
header->root = root;
sysctl_set_parent(NULL, header->ctl_table);
header->count = 1;
#ifdef CONFIG_SYSCTL_SYSCALL_CHECK
if (sysctl_check_table(namespaces, header->ctl_table)) {
kfree(header);
return NULL;
}
#endif
spin_lock(&sysctl_lock);
header->set = lookup_header_set(root, namespaces);
header->attached_by = header->ctl_table;
header->attached_to = root_table;
header->parent = &root_table_header;
for (set = header->set; set; set = set->parent) {
struct ctl_table_header *p;
list_for_each_entry(p, &set->list, ctl_entry) {
if (p->unregistering)
continue;
try_attach(p, header);
}
}
header->parent->count++;
list_add_tail(&header->ctl_entry, &header->set->list);
spin_unlock(&sysctl_lock);
return header;
}
/**
* register_sysctl_table_path - register a sysctl table hierarchy
* @path: The path to the directory the sysctl table is in.
* @table: the top-level table structure
*
* Register a sysctl table hierarchy. @table should be a filled in ctl_table
* array. A completely 0 filled entry terminates the table.
*
* See __register_sysctl_paths for more details.
*/
struct ctl_table_header *register_sysctl_paths(const struct ctl_path *path,
struct ctl_table *table)
{
return __register_sysctl_paths(&sysctl_table_root, current->nsproxy,
path, table);
}
/**
* register_sysctl_table - register a sysctl table hierarchy
* @table: the top-level table structure
*
* Register a sysctl table hierarchy. @table should be a filled in ctl_table
* array. A completely 0 filled entry terminates the table.
*
* See register_sysctl_paths for more details.
*/
struct ctl_table_header *register_sysctl_table(struct ctl_table *table)
{
static const struct ctl_path null_path[] = { {} };
return register_sysctl_paths(null_path, table);
}
/**
* unregister_sysctl_table - unregister a sysctl table hierarchy
* @header: the header returned from register_sysctl_table
*
* Unregisters the sysctl table and all children. proc entries may not
* actually be removed until they are no longer used by anyone.
*/
void unregister_sysctl_table(struct ctl_table_header * header)
{
might_sleep();
if (header == NULL)
return;
spin_lock(&sysctl_lock);
start_unregistering(header);
if (!--header->parent->count) {
WARN_ON(1);
kfree_rcu(header->parent, rcu);
}
if (!--header->count)
kfree_rcu(header, rcu);
spin_unlock(&sysctl_lock);
}
int sysctl_is_seen(struct ctl_table_header *p)
{
struct ctl_table_set *set = p->set;
int res;
spin_lock(&sysctl_lock);
if (p->unregistering)
res = 0;
else if (!set->is_seen)
res = 1;
else
res = set->is_seen(set);
spin_unlock(&sysctl_lock);
return res;
}
void setup_sysctl_set(struct ctl_table_set *p,
struct ctl_table_set *parent,
int (*is_seen)(struct ctl_table_set *))
{
INIT_LIST_HEAD(&p->list);
p->parent = parent ? parent : &sysctl_table_root.default_set;
p->is_seen = is_seen;
}
#else /* !CONFIG_SYSCTL */
struct ctl_table_header *register_sysctl_table(struct ctl_table * table)
{
return NULL;
}
struct ctl_table_header *register_sysctl_paths(const struct ctl_path *path,
struct ctl_table *table)
{
return NULL;
}
void unregister_sysctl_table(struct ctl_table_header * table)
{
}
void setup_sysctl_set(struct ctl_table_set *p,
struct ctl_table_set *parent,
int (*is_seen)(struct ctl_table_set *))
{
}
void sysctl_head_put(struct ctl_table_header *head)
{
} }
#endif /* CONFIG_SYSCTL */ #endif /* CONFIG_SYSCTL */
@ -3009,6 +2517,3 @@ EXPORT_SYMBOL(proc_dointvec_ms_jiffies);
EXPORT_SYMBOL(proc_dostring); EXPORT_SYMBOL(proc_dostring);
EXPORT_SYMBOL(proc_doulongvec_minmax); EXPORT_SYMBOL(proc_doulongvec_minmax);
EXPORT_SYMBOL(proc_doulongvec_ms_jiffies_minmax); EXPORT_SYMBOL(proc_doulongvec_ms_jiffies_minmax);
EXPORT_SYMBOL(register_sysctl_table);
EXPORT_SYMBOL(register_sysctl_paths);
EXPORT_SYMBOL(unregister_sysctl_table);

160
kernel/sysctl_check.c
View file

@ -1,160 +0,0 @@
#include <linux/stat.h>
#include <linux/sysctl.h>
#include "../fs/xfs/xfs_sysctl.h"
#include <linux/sunrpc/debug.h>
#include <linux/string.h>
#include <net/ip_vs.h>
static int sysctl_depth(struct ctl_table *table)
{
struct ctl_table *tmp;
int depth;
depth = 0;
for (tmp = table; tmp->parent; tmp = tmp->parent)
depth++;
return depth;
}
static struct ctl_table *sysctl_parent(struct ctl_table *table, int n)
{
int i;
for (i = 0; table && i < n; i++)
table = table->parent;
return table;
}
static void sysctl_print_path(struct ctl_table *table)
{
struct ctl_table *tmp;
int depth, i;
depth = sysctl_depth(table);
if (table->procname) {
for (i = depth; i >= 0; i--) {
tmp = sysctl_parent(table, i);
printk("/%s", tmp->procname?tmp->procname:"");
}
}
printk(" ");
}
static struct ctl_table *sysctl_check_lookup(struct nsproxy *namespaces,
struct ctl_table *table)
{
struct ctl_table_header *head;
struct ctl_table *ref, *test;
int depth, cur_depth;
depth = sysctl_depth(table);
for (head = __sysctl_head_next(namespaces, NULL); head;
head = __sysctl_head_next(namespaces, head)) {
cur_depth = depth;
ref = head->ctl_table;
repeat:
test = sysctl_parent(table, cur_depth);
for (; ref->procname; ref++) {
int match = 0;
if (cur_depth && !ref->child)
continue;
if (test->procname && ref->procname &&
(strcmp(test->procname, ref->procname) == 0))
match++;
if (match) {
if (cur_depth != 0) {
cur_depth--;
ref = ref->child;
goto repeat;
}
goto out;
}
}
}
ref = NULL;
out:
sysctl_head_finish(head);
return ref;
}
static void set_fail(const char **fail, struct ctl_table *table, const char *str)
{
if (*fail) {
printk(KERN_ERR "sysctl table check failed: ");
sysctl_print_path(table);
printk(" %s\n", *fail);
dump_stack();
}
*fail = str;
}
static void sysctl_check_leaf(struct nsproxy *namespaces,
struct ctl_table *table, const char **fail)
{
struct ctl_table *ref;
ref = sysctl_check_lookup(namespaces, table);
if (ref && (ref != table))
set_fail(fail, table, "Sysctl already exists");
}
int sysctl_check_table(struct nsproxy *namespaces, struct ctl_table *table)
{
int error = 0;
for (; table->procname; table++) {
const char *fail = NULL;
if (table->parent) {
if (!table->parent->procname)
set_fail(&fail, table, "Parent without procname");
}
if (table->child) {
if (table->data)
set_fail(&fail, table, "Directory with data?");
if (table->maxlen)
set_fail(&fail, table, "Directory with maxlen?");
if ((table->mode & (S_IRUGO|S_IXUGO)) != table->mode)
set_fail(&fail, table, "Writable sysctl directory");
if (table->proc_handler)
set_fail(&fail, table, "Directory with proc_handler");
if (table->extra1)
set_fail(&fail, table, "Directory with extra1");
if (table->extra2)
set_fail(&fail, table, "Directory with extra2");
} else {
if ((table->proc_handler == proc_dostring) ||
(table->proc_handler == proc_dointvec) ||
(table->proc_handler == proc_dointvec_minmax) ||
(table->proc_handler == proc_dointvec_jiffies) ||
(table->proc_handler == proc_dointvec_userhz_jiffies) ||
(table->proc_handler == proc_dointvec_ms_jiffies) ||
(table->proc_handler == proc_doulongvec_minmax) ||
(table->proc_handler == proc_doulongvec_ms_jiffies_minmax)) {
if (!table->data)
set_fail(&fail, table, "No data");
if (!table->maxlen)
set_fail(&fail, table, "No maxlen");
}
#ifdef CONFIG_PROC_SYSCTL
if (!table->proc_handler)
set_fail(&fail, table, "No proc_handler");
#endif
sysctl_check_leaf(namespaces, table, &fail);
}
if (table->mode > 0777)
set_fail(&fail, table, "bogus .mode");
if (fail) {
set_fail(&fail, table, NULL);
error = -EINVAL;
}
if (table->child)
error |= sysctl_check_table(namespaces, table->child);
}
return error;
}

8
lib/Kconfig.debug
View file

@ -1141,14 +1141,6 @@ config LATENCYTOP
Enable this option if you want to use the LatencyTOP tool Enable this option if you want to use the LatencyTOP tool
to find out which userspace is blocking on what kernel operations. to find out which userspace is blocking on what kernel operations.
config SYSCTL_SYSCALL_CHECK
bool "Sysctl checks"
depends on SYSCTL
---help---
sys_sysctl uses binary paths that have been found challenging
to properly maintain and use. This enables checks that help
you to keep things correct.
source mm/Kconfig.debug source mm/Kconfig.debug
source kernel/trace/Kconfig source kernel/trace/Kconfig

24
net/sysctl_net.c
View file

@ -74,15 +74,13 @@ static struct ctl_table_root net_sysctl_ro_root = {
static int __net_init sysctl_net_init(struct net *net) static int __net_init sysctl_net_init(struct net *net)
{ {
setup_sysctl_set(&net->sysctls, setup_sysctl_set(&net->sysctls, &net_sysctl_root, is_seen);
&net_sysctl_ro_root.default_set,
is_seen);
return 0; return 0;
} }
static void __net_exit sysctl_net_exit(struct net *net) static void __net_exit sysctl_net_exit(struct net *net)
{ {
WARN_ON(!list_empty(&net->sysctls.list)); retire_sysctl_set(&net->sysctls);
} }
static struct pernet_operations sysctl_pernet_ops = { static struct pernet_operations sysctl_pernet_ops = {
@ -90,36 +88,32 @@ static struct pernet_operations sysctl_pernet_ops = {
.exit = sysctl_net_exit, .exit = sysctl_net_exit,
}; };
static __init int sysctl_init(void) static __init int net_sysctl_init(void)
{ {
int ret; int ret;
ret = register_pernet_subsys(&sysctl_pernet_ops); ret = register_pernet_subsys(&sysctl_pernet_ops);
if (ret) if (ret)
goto out; goto out;
register_sysctl_root(&net_sysctl_root); setup_sysctl_set(&net_sysctl_ro_root.default_set, &net_sysctl_ro_root, NULL);
setup_sysctl_set(&net_sysctl_ro_root.default_set, NULL, NULL);
register_sysctl_root(&net_sysctl_ro_root); register_sysctl_root(&net_sysctl_ro_root);
register_sysctl_root(&net_sysctl_root);
out: out:
return ret; return ret;
} }
subsys_initcall(sysctl_init); subsys_initcall(net_sysctl_init);
struct ctl_table_header *register_net_sysctl_table(struct net *net, struct ctl_table_header *register_net_sysctl_table(struct net *net,
const struct ctl_path *path, struct ctl_table *table) const struct ctl_path *path, struct ctl_table *table)
{ {
struct nsproxy namespaces; return __register_sysctl_paths(&net->sysctls, path, table);
namespaces = *current->nsproxy;
namespaces.net_ns = net;
return __register_sysctl_paths(&net_sysctl_root,
&namespaces, path, table);
} }
EXPORT_SYMBOL_GPL(register_net_sysctl_table); EXPORT_SYMBOL_GPL(register_net_sysctl_table);
struct ctl_table_header *register_net_sysctl_rotable(const struct ctl_table_header *register_net_sysctl_rotable(const
struct ctl_path *path, struct ctl_table *table) struct ctl_path *path, struct ctl_table *table)
{ {
return __register_sysctl_paths(&net_sysctl_ro_root, return __register_sysctl_paths(&net_sysctl_ro_root.default_set,
&init_nsproxy, path, table); path, table);
} }
EXPORT_SYMBOL_GPL(register_net_sysctl_rotable); EXPORT_SYMBOL_GPL(register_net_sysctl_rotable);